(1) Field of the Invention
The present invention relates to a 5xe2x80x2 upstream region DNA containing a promoter of a human bone morphogenetic protein (BMP, hereafter-4). Further, the present invention relates to a method for exploring a low molecular weight compound positively or negatively which regulates the expression of human BMP-4 by using a mass of animal or yeast cells that are introduced with a 5xe2x80x2 upstream region DNA containing the human BMP-4 promoter and a recombinant expression vector integrated into a suitable reporter gene, and by using a reporter activity as an indicator.
(2) Description of the Related Art
At present, a bone morphogenetic activity has been reported for a bone morphogenetic factor, BMP, belonging to TGF (transforming growth factor) -xcex2 superfamily (Science 150, 893-897, 1965; Science 242: 1528-1534, 1988). Known species of BMP are BMP-1 to BMP-14. Among them, the members from BMP-2 to BMP-14 have been known as showing the bone morphogenetic activity. BMPs ranging from BMP-2 to BMP-14 are considered as effective to therapeutic and preventive treatment for various bone dysfunction and bone diseases, however, they exist in very small amount in nature. Therefore, an available large quantity from BMP-2 to BMP-14 used for these treatments requires production of recombinant protein. The production of the recombinant protein generally is very expensive compared with a low molecular weight compound. On the other hand, there are many restrictions as a medical drug in terms of physical properties and administration due to its proteinic characteristics. Considering these points, a small molecular organic compound having the equal activity to that of said BMP protein, if any, will become a very promising medical drug. The substance obtained by the exploring method provided by the present invention has the activity to induce the expression of human BMP-4, a bone morphogenetic protein, and also has the same activity as that of human BMP-4 to be a very useful application. On the contrary, there is a report (New Engi. J. Med., Vol. 335, p. 555-561, 1996) suggesting that human BMP-4 causes bone and cartilage hyperplasia. In this case, inhibiting the expression of human BMP-4 may prevent osteohyperplasia. The present invention is able to detect the inhibition of the expression of human BMP-4 and provides a method for exploring a substance which prevents such hyperplasia.
For such an exploring method, an example was so far only reported using a murine BMP-2 promoter (WO97/15308) ; there is no example of using a human BMP-4 promoter. The region of the murine BMP-4 promoter has been already cloned (Biochem. Biophys. Acta, Vol. 1218, p. 221-224, 1994), but no detailed sequence data of the human BMP-4 promoter has been elucidated. The present invention first disclosed the sequence of the human BMP-4 promoter. The homology of the entire sequence of 5xe2x80x2 upstream region DNA between human and murine BMP-4 (J. Biol. Chem., Vol. 270, p. 28364-28373, 1995) is 52.2%. The materials for the exploring method provided by the present invention are-all derived from human sources so that the substance obtained by the exploration would be a clinical application practically. It is expected to obtain a substance capable of more accurate regulation of the human BMP-4 expression by transfecting two promoters (promoter 1 and promoter 2) separately or simultaneously in the recombinant expression vector into the host cells.
The present invention provides a 5xe2x80x2 upstream region DNA containing a promoter of human BMP-4. By using 5xe2x80x2 upstream region gene containing the human BMP-4 promoter and an animal cell introduced with a recombinant expression vector which has been integrated in an appropriate reporter gene, the low molecular weight compounds which regulate positively or negatively the expression of human BMP-4 can be explored with reference to a reporter activity. The low molecular weight compounds and their derivatives have morphogenetic activity and inhibiting activity for bone and cartilage through the expression of human BMP-4 and are useful as preventive or therapeutic agents for cartilage and bone diseases, remedies for osteometastasis, or therapeutic and preventive agents for osteohyperplasia.